Project HYDRA

Wednesday, 20 January 2010 17:08
administrator

Presently, digital continuous media (CM) are well established as an integral part of many applications. In recent years, a considerable amount of research has focused on the efficient retrieval of such media. Scant attention has been paid to servers that can record such streams in real time. However, the current technological trends are such that more and more sensor devices (e.g., cameras) can directly produce digital data streams. Furthermore, some of these new devices are network-capable either via wired (SDI, Firewire) or wireless (Bluetooth, IEEE 802.11x) connections. Hence, the need arises to capture and store these streams with an efficient data stream recorder that can handle both recording and playback of many streams simultaneously and provide a central repository for all data.

Our research activities are focusing on the design and implementation of a High-performance Data Recording Architecture (HYDRA). The goal of HYDRA is to improve current and enable new applications by acting as an efficient media stream coordinator that manages the transmission, recording, and playback of many different data streams simultaneously. The objective of HYDRA is to use a unified paradigm that integrates multi-stream recording, retrieval and control in a synergetic manner. HYDRA aims to provide the same services for all media, independent of their bandwidth requirements, resolution or modality. One of the applications that we are exploring for this technology is a Distributed Immersive Performance where musicians and audiences are geographically disbursed in different locations.

The HYDRA architecture is based on a scalable cluster design. Each cluster node is a off-the-shelf personal computer with attached storage devices and, for example, a Fast Ethernet connection. The HYDRA server software manages the storage and network resources to provide real-time service to the various clients that are requesting media streams.

The design goals of our architecture can be summarized as follows:

Provide support for the real time recording of multiple, concurrent streams that are of various media types. For example, streams may be received at different average bit rates and be encoded with constant (CBR) or variable bit rate (VBR) techniques.

Provide support for the synchronized recording of multiple streams.

Be a modular, scalable architecture.

Use unified algorithms (e.g., data placement and scheduling) that can accommodate both recording and playback simultaneously in any combination with low latency.

We have performed experiments across both LAN and WAN environments. Our most recent tests were conducted via a two-way, trans-pacific Internet2 link between the East West Center at the University of Hawaii in Honolulu, and the USC campus in Los Angeles, CA.